+ Chapter 2 Personality Assessment, Measurement, and Research Design

+ Sources of Personality Data Self-Report Data (S-Data) Observer-Report Data (O-Data) Test-Data (T-Data) Life-Outcome Data (L-Data) 2

+ Self-Report Data (S-Data) ________________________________________________________ ________________________________________________________ Individuals have access to a wealth of information about themselves that is inaccessible to anyone else S-data personality tests Unstructured items—open-ended Structured items—response options provided Limitations of S-data ____________________________________________________________ People may lack accurate self-knowledge 3

+ Observer-Report Data (O-Data) _________________________________________ _________________________________________ Key features of O-data Provide access to information not attainable through other sources Multiple observers can be used to assess a person 4

+ Observer-Report Data Selecting observers Professional personality assessors People who actually know the target person Often in better position to observe target’s natural behaviors than professional personality assessors Allows for assessment of multiple social personalities Because of relationship to target, however, observer may be biased 5

+ Observer-Report Data Naturalistic vs. Artificial Observation Naturalistic observation: __________________________________________________________ __________________________________________________________ Has the advantage of being able to secure information in realistic context, but at the cost of not being able to control events witnessed Artificial observation: __________________________________________________________ Has the advantage of controlling conditions and eliciting relevant behavior, but at the cost of sacrificing realism 6

+ Test-Data (T-Data) Information provided by standardized tests or testing situations ________________________________________________________ ________________________________________________________ Situation designed to elicit behaviors that serve as indicators of personality Elicited behavior “scored” without reliance on inference 7

+ Test-Data Limitations ____________________________________________________________ ____________________________________________________________ ____________________________________________________________ Difficult to know if participants define testing situation as intended by experimenter Researcher might influence how participants behave 8

+ Test-Data ________________________________________________ (e.g., “Actometer” used to assess children’s activity) Strengths Not hampered by biases of human observer May be used in naturalistic settings Disadvantage Few personality dispositions lend themselves to mechanical assessment 9

+ Test-Data Physiological data Includes information about a person’s level of arousal, reactivity to stimuli—potential indicators of personality _____________________________________________________________ Areas of the brain “light up” when performing certain tasks such as verbal problems or spatial navigation problems It works by gauging the amount of oxygen brought to particular places in the brain When a certain part of the brain is highly activated, it draws large amounts of blood (fMRI detects iron in red blood cells) _____________________________________________________________ Disadvantages Often used in artificial laboratory setting Accuracy of recording hinges on whether participant perceives situation as experimenter intended 10

+ Test Data Projective Techniques Person presented with ambiguous stimuli and asked to describe what she sees; assumption is that person “projects” personality onto ambiguous stimuli Strengths: May provide useful means for gathering information about wishes, desires, fantasies that a person is not aware of and could not report ____________________________________________________________ ____________________________________________________________ 11

+ Life-Outcome Data (L-Data) ________________________________________________________ ________________________________________________________ ________________________________________________________ (e.g., marriages and divorces, speeding tickets, gun ownership, arrest record, products produced – books published, music recorded) Can serve as important source of “real life” information about personality Oftentimes S-data and O-data will be used to predict L-data e.g., O-data from mothers’ reporting on the severity and frequency of their children’s (8-10 years old) temper tantrums predicted their life outcomes as adults (30-40 years old) High severity/frequency temper tantrums as a child predicted increased likelihood for divorce in both men and women 12

+ Issues in Personality Assessment Links among different data sources When they do and do not exist and how to interpret these linkages In other words, for example, agreement between S-data and O-data between a husband and wife Husband’s report of his verbally aggressive behavior and wife’s observed report of his verbally aggressive behavior Depending on the personality variable under consideration, agreement across data sources tends to range from low to moderate Fallibility of personality measurement All sources of data have limitations _______________________________________________________________ _______________________________________________________________ 13

+ Evaluation of Personality Measures Reliability Validity Generalizability 14

+ Reliability Degree to which an obtained measure provides consistent results (under consistent conditions) Types of reliability _______________________ – scores at one administration positively correlate with scores at a second administration _______________________ – ratings provided by one observer correlate with ratings provided by another observer _________________________________– items within a test positively correlate 15

+ Validity Degree to which test measures what it claims to measure Types of validity __________________– whether the test, on the surface (i.e., the questions), appears to measure what it is supposed to measure ____________________________ – whether a test predicts external criteria to the test (e.g., measuring trait “x” will predict behavior/outcome “a” in the future) _______________________ – how well a test correlates with other measures that it should correlate with _______________________ – how well a test does not correlate with other measures it should not correlate with __________________ – a test that measures what it claims to measure, correlates with what it is supposed to correlate with, and does not correlate with what it is not supposed to correlated with A broad, overarching definition of validity 16

+ Generalizability ________________________________________________________ ________________________________________________________ ________________________________________________________ Generalizability subsumes reliability and validity Greater generalizability not always better; what is important is to identify empirical contexts in which a measure is and is not applicable 17

+ Research Designs in Personality Experimental Methods Correlational Studies Case Studies 18

+ Experimental Methods Used to determine ______________—whether one variable causes another Two key requirements: Manipulation of variables – ___________________________________ ______________________________________________________________ ____________________________________________________________ __ Ensuring that participants in each experimental condition are equivalent to each other 19

+ Correlational Studies Correlation is a statistical procedure for determining whether there is a _______________________________________ Designed to identify “what goes with what” in nature, and ________________________________________________________ Major advantage is that it allows us to identify relationships among variables as they occur naturally 20

+ Correlational Studies Correlation coefficient varies from –1 (perfect negative relationships) through 0 (no relationship) to +1 (perfect positive relationship) Correlation does not indicate causation ____________________________ 21

+ Case Studies In-depth examination ____________________________________ Advantages Can find out about personality in great detail Can give insights into personality that can be used to formulate a more general theory that is tested on a larger sample Can provide in-depth knowledge about an outstanding figure, such as a political or religious figure Disadvantage Results based on the study of single person ____________________ ______________________________________________________________ 22

+ When to Use Experimental, Correlational, and Case Study Designs Each design has strengths and weakness; strength of one is weakness of another Which design a researcher uses depends on the research question and the goal of research Taken together, three designs provide complementary methods for exploring personality 23

+ Summary and Evaluation Decisions about data source and research design depend on the purpose of study There is no perfect data source There is no perfect research design But some data sources and some methods are better suited for some purposes than for others 24